SPM KIMIA K3

CHEMISTRY SPM 29 IMTIAZ

CEMERLANG SPM 2012 YAYASAN TERENGGANU

4541/3 : CHEMISTRY Paper 3

1 Diagram 1.1 shows the set-up of apparatus used in an experiment to construct the electrochemical

series by referring to the potential difference of four pairs of metals.

Rajah 1.1 menunjukkan susunan radas yang digunakan dalam satu eksperimen untuk membina siri

elektrokimia dengan merujuk kepada beza keupayaan bagi empat pasangan logam.

Diagram 1.1

Rajah 1.1

Diagram 1.2 shows the result obtained from the experiment after 30 minutes.

Rajah 1.2 menunjukkan keputusan yang diperoleh daripada eksperimen selepas 30 minit.

Diagram 1.2

Rajah 1.2

Copper electrode

Elektrod kuprum Zinc electrode

Elektrod zink

Copper(II) sulphate solution

Larutan kuprum(II) sulfat

V

V Copper electrode

Elektrod kuprum

Zinc electrode

Elektrod zink





(a) State three different observations and the corresponding inferences in Table 1.3.

Nyatakan tiga pemerhatian yang berbeza dan inferens yang sepadan dalam Jadual 1.3.

Observation Pemerhatian

Inference Inferens

1

2

3

Table / Jadual 1.3

[6 marks]

(b) The experiment is repeated by replacing zinc with metals P, Q and R. Copper

electrode remains as the positive terminal in each of the experiments. Fresh copper(II)

sulphate solution is used in each of the experiments.

Eksperimen diulangi dengan menggantikan zink dengan logam P, Q dan R. Elektrod kuprum

kekal sebagai terminal positif bagi setiap eksperimen. Larutan kuprum(II) sulfat yang baru

digunakan bagi setiap eksperimen.

Diagram 1.4 shows the voltmeter readings of the experiments.

Rajah 1.4 menunjukkan bacaan voltmeter bagi semua eksperimen.

Reading: Bacaan: …………………….


Zinc and Copper

Zink dan kuprum P and Copper P dan kuprum





Diagram 1.4

Rajah 1.4

Record the voltmeter readings in the spaces provided in Diagram 1.4.

Catatkan bacaan voltmeter pada ruang yang disediakan dalam Rajah 1.4.

[3 marks]

(c) Construct a table to record the voltmeter reading for four pairs of metals.

Bina satu jadual untuk merekodkan bacaan voltmeter untuk empat pasangan logam.

[3 marks]

Q and Copper

Q dan kuprum

R and Copper R dan kuprum



(d) Based on the voltmeter readings and the copper electrode that acts as the positive terminal in

pair of metals, arrange metals Zn, Cu, P, Q, and R in ascending order of electropositivity of

metals in the electrochemical series.

Berdasarkan bacaan voltmeter dan elektrod kuprum yang bertindak sebagai terminal positif,

susun keelektropositifan logam-logam Zn, Cu, P, Q dan R secara tertib menaik dalam siri

elektrokimia.

…………………………………………………………………………………………………

[3 marks]

(e) Based on this experiment, state the :

Berdasarkan eksperimen ini, nyatakan :

(i) Manipulated variable

Pemboleh ubah dimanipulasikan

…………………………………………………………………………………………

(ii) Responding variable

Pemboleh ubah bergerak balas

…………………………………………………………………………………………

(iii) Constant variable

Pemboleh ubah dimalarkan

…………………………………………………………………………………...............

[3 marks]

(f) State the hypothesis for the experiment.

Nyatakan hipotesis bagi eksperimen ini.

…………………………………………………………………………………………………

[3 marks]

(g) State the operational definition for the potential difference.

Nyatakan definisi secara operasi bagi beza keupayaan.

…………………………………………………………………………………………...……..

[3 marks]

(h) Classify all the ions present in copper(II) sulphate solution into cations and anions.

Kelaskan ion-ion yang terdapat di dalam larutan kuprum(II) sulfat kepada kation dan anion.

Cations Kation

Anions Anion

[3 marks]



(i) Predict the positive terminal and the voltage for the pair of metals P and Q.

Ramalkan terminal positif dan nilai voltan bagi pasangan logam P and logam Q.

Pair of Metals Pasangan logam

Positive Terminal Terminal Positif

Voltage / V Voltan / V

P and Q P dan Q

[3 marks]

(j) A student carried out two experiments as shown in Diagram 1.5.

In the experiments, zinc and magnesium electrodes corroded.

Seorang pelajar menjalankan dua eksperimen seperti dalam Rajah 1.5.

Di dalam eksperimen-eksperimen ini, elektrod zink dan magnesium terkakis.

Diagram 1.5

Rajah 1.5

Based on the experiments, zinc electrode takes a longer time to corrode compared to

magnesium electrode. Explain why.

Berdasarkan eksperimen, elektrod zink memerlukan masa yang lebih panjang untuk terkakis

berbanding dengan elektrod magnesium. Terangkan mengapa.

……………………………………………………………………………………………….....

…………………………………………………………………………………………….....…

……………………………………………………………………………………………….....

……………………………………………………………………………………………….....

[3 marks]



V Copper electrode

Elektrod kuprum

Zinc electrode

Elektrod zink

V Magnesium electrode

Elektrod magnesium

Copper electrode

Elektrod kuprum



2 Combustion of alcohol gives out heat energy. Table 2.1 shows the amount of heat given out when

different alcohols are burnt.

Pembakaran alkohol membebaskan tenaga haba. Jadual 2.1 menunjukkan nilai haba yang

dibebaskan apabila alkohol-alkohol yang berbeza dibakar.

Table 2.1

Jadual 2.1

Based on the information in table 2.1, plan an experiment to determine the heat of combustion of

the alcohols.

Berdasarkan kepada maklumat dalam jadual 2.1, Rancang satu eksperimen untuk menentukan

haba pembakaran bagi alkohol-alkohol tersebut.

Your planning should include the following aspects:

Perancangan anda haruslah mengandungi aspek berikut:

(a) Aim of the experiments

Tujuan eksperimen

(b) All the variables

Semua pembolehubah

(c) Statement of the hypothesis

Penyataan hipotesis

(d) List of substances and apparatus

Senarai bahan dan alat radas

(e) Procedure of the experiment

Prosedur eksperimen

(f) Tabulation of data

Penjadualan data

(17 marks)

Alcohol

Alkohol

Heat of combustion

Haba pembakaran

/ ΔH (kJ mol-1

)

Methanol -728

Ethanol -1376

Propanol -2016



SAMPLE ANSWER Paper 3

Question 2 :

(a) Aim of the experiment :

To determine the ………………….. of methanol, ethanol and

propanol /different alcohols

(b) Variables :

Manipulated variable :

………………………………………………………….

Responding variable :

………………………………………………………….

Constant variable : Volume of water // Copper/metal can

(c) Hypothesis :

The …………….. the number of carbon atom per molecule, the

…………….… the heat of combustion.

(d) Substances :

(Methanol, ethanol and propanol)/alcohols, water

Apparatus :

Copper/metal can, thermometer, weighing balance, spirit lamp,

wooden block, pipe-clay triangle and tripod stand.



(e) Procedure :

1. 100 cm3 of water is ………………….. and poured into a copper can.

2. The initial temperature of the water are measured and …………………..

3 About 50 cm3 of methanol is poured into a spirit lamp.

The mass of spirit lamp and its contents is weighed and ………………….

4. The spirit lamp is placed under the copper can.

5. The spirit lamp is lighted ……………………...

6. When the temperature of water rises by 30 oC, the flame is put off.

7. The spirit lamp is weighed quickly and the highest temperature reached

by the water is ……………………...

8. Steps 1 to 7 is ………………… with ethanol and propanol.



END OF MODULE

(f) Tabulation of data :

Type of alcohol Methanol Ethanol Propanol

Initial mass of spirit lamp / g

Final mass of spirit lamp / g

Mass of alcohol burnt / g

Initial temperature of water/ oC

Highest temperature of water / oC

Temperature change / oC

SPM KIMIA K3

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